Then, shortly after a Massachusetts Institute of Technology campus officer was shot and killed, police got reports of an armed carjacking of a black Mercedes SUV nearby. The brothers had forced the vehicle's driver to get them money from ATMs in the area. At a Shell station in Cambridge, the security camera provided "extremely good video of two suspects," a clear match with the photos from Boylston Street, Davis said.
In a violent confrontation with police in Watertown shortly after the carjacking episode, Tamerlan left the SUV and Dzhokhar, behind the wheel, tried to mow down police officers. In the process, he hit his brother, who was dragged under the car. Tamerlan died later that night. Police positively identified him by comparing his fingerprints against government records, Davis said.
The police commissioner said releasing images of the brothers may have spurred their violent spree. "We may have forced their hand by releasing the video," he said. But he said that was nonetheless the right move: "I truly believe they were planning more attacks based in the arsenal I saw in Watertown. By forcing their hand we saved a much larger loss of life. . . . These individuals were bent on murder and mayhem."
After a tense day of searches on the silent streets of a locked-down city, David Henneberry was eager to get some air. As soon as authorities lifted the stay-inside order Friday just before dusk, Henneberry stepped out of his Watertown house.
Something about his boat seemed off. The plastic cover was flapping in the wind, which made no sense, especially given that Henneberry had tied it down so well that it hadn't moved even through this winter's blizzards.
On inspection, the cover appeared to have been sliced open. Then Henneberry saw the blood. He came closer, pulled himself up a ladder to peer inside and saw more blood — and a curled-up form.